Question

The metal with the lowest density among the given options is:
$
  {\text{A}}{\text{. Mg}} \\
  {\text{B}}{\text{. Li}} \\
  {\text{C}}{\text{. Ag}} \\
  {\text{D}}{\text{. Au}} \\
$

Answer 1

Hint – To find out the metal with lowest density, we identify all the elements in the given choices and look into their respective densities.

Complete answer:
Mg stands for Magnesium and its density is 1.738 $\dfrac{{\text{g}}}{{{\text{c}}{{\text{m}}^3}}}$
Li stands for Lithium and its density is 0.534 $\dfrac{{\text{g}}}{{{\text{c}}{{\text{m}}^3}}}$
Ag stands for Argentum also known as Silver and its density is 10.49 $\dfrac{{\text{g}}}{{{\text{c}}{{\text{m}}^3}}}$
Au stands for Aurum also known as Gold and its density is 19.30 $\dfrac{{\text{g}}}{{{\text{c}}{{\text{m}}^3}}}$
Under standard conditions, lithium is the lightest metal and the least dense solid element. It is a soft, silver-white metal belonging to the alkali metal group of chemical elements.

Hence, Option B is the correct answer.

Note – In order to answer this type of question the key is to be well aware of all the existing elements and their symbols. Density of an element is not necessarily the same at any given condition, it may change due to change in the temperature or pressure of the surroundings. Therefore while comparing the densities of elements above, we consider all of them to be under standard conditions.
Density of an element is given by${\text{D = }}\dfrac{{{\text{Mass of the element}}}}{{{\text{Volume of the element}}}}$.